Diaphragm and method for making same



' o 9 1,645 110 Oct 1 c. MESSlCK l DIAPHRAGM ANDJMETHOD FOR MAKING SAME Original Filed Oct. 1. 1919 2 Sheets-sheet 1 I 1,645,110 C.MESSICK I DIAPHRAGM AND METHOD FOR MAKING SAME Original Filed Oct. 1, 191 2 Sheefis-sneet 2 Patented a. 11, 1927.

um'rsn STATES PATENT, OFFICE.

cmnnns MESSIGK, or amniv'rwoon, new YORK.

nmnnaem Aim mn'rnon FOR MAKING same.

Application 111m October 1, 1919, Serial No. 327,799. Renewed August 5, 1925.

My invention relates to diaphragms of the general type described in my applica tion Serial No. 212,568, filed Jan. 19, .1918,

Patent No. 1,503,696, dated Aug. 5 192 1.

6 The broad object of my invention is to provide a stationary peripheral anchorage means with an improved vibratory dia-- phragm under one or more kinds of tension anchored at the means.

Among the specific objects are the following I. To incorporate within the diaphragm means, said members being covered with an imperforate means. a

III. To incorporate within the diaphragm structure a skeleton framework arranged to sustain as far as practicable various meg chanical strains, and a web separate from said framework and so mounted thereupon as to expose to the air an imperforate surface of large area.

IV. To incorporate-within the diaphragm structure a skeleton framework having a stiff central portion and a flexible peripheral portion, said framework as a whole carrying a a single web only, in order, to render the diaphragm light.

V. To incorporate within the diaphragm structure a number of threads crossing each other at a common center, each thread'being under tension and so connected that'the several threads are formed into a cone, the apex 40 of which is the crossing point of the threads.

VI. To provide a tensioned vibratory diaphragm anchored at its edge to a stationary anchorage ring or frame and subjected to tension including both radial and chordal components; the radial components being like those in tensioned spokes in a wheel and the chordal components being like those in a drum head made of stretched woven fabric or conventional drumhead material, ,in

which the radial tension at the center is so small as to be inadequate and even negligible for effectively communicating motion to or receiving motion from the center of a transmitter or receiver diaphragm.

Other objects will appear from the following description of the preferred construction and be pointed out in the claims.

, Some of the improvements in the diaphragm and in the method of making it consist of building the diaphragm of stretched radial threads crossing one another in pairs at the center; connecting the radial threads by a stretched membrane; providing a central strut to separate theradial threads into upper and lower -groups; and tying and stitching the radial threads and the membrane-together, part way between the center and the periphery, so that the central portion is formed into a stretched cone with the strut under compression, while the portionv external to the stitching is fiat. Other im-' provements will appear in the following description and claims.

Referring to the accompanying drawings the figures, which are somewhat diagrammatic, indicate progressive steps in the method of constructlon of my diaphragm, except that in Figs. 1 to 8, inclusive, the membrane fabric, which is pasted on the bottom of the hook ring in the first operation, is omitted to show the other parts and the methods of their assembly more clearly. This membrane fabric is shown for the first time in Fig. 9. i

Fig. 1 is a plan view of a hook ring pro vided with pins and wound loosely with a radial thread provided with a loose draw thread;

Fig. 2 is a section taken on the line 2+2 of Fig. 1, but with the loose threads omitted.

Fig. 3 is a plan view and shows the hook ring as in Fi 1, but with the .radial thread tightened an fastened by the draw thread to the lower end of the strut;

Fig. 4 is a section taken on theline 4-4 of Fig. 3;

Figs. 5 and 6 correspond to Figs. 3 and 4, res ectively, but the threads are depressed an held to a board by thumb tacks;and additional loose radial and draw threads are shown;- 1

In Figs. 7. and 8, which correspond to Figs 5; and ,6, respectivelygthe thumb tacks have been removed. and they loose radial thread of Figs-5 and dis shown tightened and fastened by the draw thread to the top of the strut;

Figs. 9 and lO correspond to Figs. 7 and 8, but also indicate-the membranefabric pasted onthe top of the hook ring, the ties connecting the I upper and lower radial threads together to form a centrally disposed cone, and the stitching connecting then embrane fabric to the radial threads; 7'

Fig. 11 is an enlarged fragmentary View showing the relative positions pf the radial" and'draw threads at the strut, as seen in a smaller scale in Fig. 7

Fig. 12 "s an enlarged fragnientary' plan view including the assembly of Fig. 9 which is inverted in this figure, thestructure being provided with an elastic reinforcement washerdand stretched upon a stretching frame; an p 13' is a section on line 1313 of :Fig.12.

The numeral 100 indicates a hook ring which resembles the hook rings'of banjos,

and is provided With pins 101, 102, 103, 104,

hold radial threads.

105, 106, 107and'108, to

A radial silk thread 109 is provided with Y a loop 110'which encircles the pin 103. This *thread 109 extends loosely according to Fig.

I, up and around pin 108; across the central portion of the hook ring 100, around pin 105' and pin 104; across the central portion of the hook ring 100, around pin 101, and to the left around the pin 106; across the central 1 portion of hook ring 100, and around the pin .103, and around the pin 102; across the central (portion of the hook 'ring 100, around the pin 107; then down and terminates in a loop III, which encirclesthe pin 104.

It will be noted that the portions of this .lradialthread 109 external'to the hook ring 100 are symmetrical with respect to the internalportions, in that when the thread is Jt1ghtened,.as will be subsequently described,

the tension of the several portions of the thread 109 within the hook ring aresubstantially equal. 1 ilt will also be noted that the portions ,of the radial thread 109 crossing the hook ring100 are formed in parallel pairs which facilitates their attachment to the strut 114, to beifurther described. I

Referring to Fig. .1, a silk draw thread 112 having ends 1120 and 113 is-introduced alternately above and below each pair of .parallel portions ofthe radial thread 109.

Commencing at the end numbered 1120,

thread 112 extends beneath thread 109 near pins 104 and 105, above near pins 106 and 107, beneath near pins 108 and 101, above near pins 102 and, 103 and ends at' 113. The end 113 of'the drawthread 112 is then tightened, tied 'to its first mentioned end 1120'and' drawsthe radial'thread'109 into its partially tensioned radial position as indicated in Fig. 3, and encircling the lower reduced diameter end portion 115 vof the strut 114, as particularly shown in Fig.4. The two portions of the radial thread109 composing. each pair, extend one on each theatre f indicated.

' side of the strut 114: at the same level,thus

securing a symmetricalattac pression upon the strut. R ferring to Figs. 5 and 6,

hment and comin which. the position of-thehook ring 100 corresponds respectively to its position in Figs. 3 and 4, the radial thread 109 is indicated'as held down by thumb tacks 117 onto a board, 118,- i

so that anadditional silk radial thread 120, and a silk draw thread 123, may be applied. The additional radial thread 120 is provided With terminal loops 119 and 121, and is placed in position in exactly the same manner as radial thread 109 of Fi 1. It encircles the same pins and its raw thread 122, having ends respectively numbered 1220 and 123, is tied in the same manner as draw. j,

threads 112, excepting that, it is tied-around the upper reduced diameter end portion 116 of strut 114, as indicated Figs. 7 and 8.

particularly in A silk membrane fabric 124, firstshown in Figs. 9 and 10 with pins 101 to 108 picjecting through it, Was pasted upon the hook ring 100 before any ofthe threads previous. ly described were applied, and this membrane fabric has for its function the closing of the spaces between the radial threads of the diaphragm and also providing" chordal tension for the vibratory portion of the diaphragm. I

In Figs. 9 and 10 the silk tie threads 12 5 holding together the parallel radial portions of radial threads 109 and 120 are indicated,

and silk stitches 126 attaching the membrane fabric 124 to the radial threads 109 and 120 are also shown. These tie threads and stitches form the radial threads into the'central double cone of the diaphragm, which is.

ofgreat stiffness as compared to the external flat portion of the diaphragm. Vibrations; move the entire conical portion as a unit with a piston action, while the distortion peripheral portion. v

Referring to Fig. 11, which is an enlargecaused by each vibration occurs in the flat ment of the central portion of Fig. 7, the

rel itive positions of the radial thread 120,

.the draw thread 122, the strut 114, and its upper end portion 116 are shown and the ends of the knot of draw thread 112 are also Referring to Figs. 12 and 13, the assembly of Figs. 9 and 10 is inverted and provided with an elastic reinforcing washer 127, fitted upon the pins ;101'to 108 to reinforce-the peripheral portion of the diaphragm which is then stretched upon the cylindrical portion 128 of the stretching frame 129. Hook bolts 130, provided with adjustable lock nut stops 131, and thumb nuts 132 are used to draw the hook ring 100 down and "stretch;

the diaphragm evenly upon the stretching frame129. A p I Thediaphragm is then coated with a "resonant varnish or adhesive coatin to make it air tight'and to secure the ra ial threads throughout their entire brane fabric.

While the hook ring has been indicated lengths to the memwith only eight pins, in practice any number of pins, preferably a large number, may

be used.

Modifications of the diaphragm and the methods for making same in accordance with the progress of the art may be made, and one or more of the novel elements may be used singly or in combination without departing from the spirit of the invention.

I claim -1. A diaphragm provided with a stationary peripheral anchorage means and a vibratory portion including a. skeleton framework having an attachment portion and several tensioned radial elements extending therefrom to the means, and imperforate means united '-to the framework-throughout the portion of its area adjacent the. framework. I

2. A diaphragm rovided with a stationary peripheral anc orage means and a vibratory portion including a skeleton framework having an attachment portion and several tensioned radial elements extending .therefrom to the'means, and tensioned 1mperforate means united to .the framework throughout the the framework.

3. A diaphragm comprising a stationary frame, a vibratory skeleton framework within the frame consisting of a central compression member, radial tensioned members extending from both top and bottom of the portion of its area adjacent compression member, held together inter-- mediate the central compression member and the stationary frame, thence extending in a common plane to the'stationary frame,

and imperforate means united to the vibratory framework throughout the portion of its area adjacent the framework.

4. In a diaphragm. structure, the combination of a plurality of long threads radiating from a common centre, each under tension, and aflexible web mounted .upon I said threads and united thereto where adjacent to the threads.

5. A diaphragm provided with a flat peripheral portion and a central double conical portionhaving a member under compression included between radially tensioned members.

6. .Ajdia hragm comprising a number of separate tensioned members crossing each ot er at a common centre and under strain;

said tension.v members being so connected that they assume the form of adouble cone.

7. A stretching frame, a framework, in-

cluding severalradial members stretched onthe frame and a member imperforate to air. connected to the framework throughout the adjacent portions of the member and framework whereby the memberand framework ma vibrate in synchronism. V

8. A iaphragm including a number of separate radially tensioned members crossing each other at a common center and under strain, some of said members being compressed between other of sald'members.

9. A diaphragm including a number of separate radially tensioned members crossing each other at-a common center and under strain, some of, said members being compressed between other of said members and a strut to space half of said members away from the other half of said members.

10. The combination of a stationary anchorage frame provided with avibratory diaphragm anchored at the frame and tensioned both radially and chordally.

11. A diaphragm structure including a stationary, peripheral stretching frame, a

vibratory portion mounted therein and having a. center, said vibratory portion being tensioned at the frame along many radii, having substantially the same cross-sectional area under radial tension at all imaginary concentric sections thereof said vibratory portion also including means tensioned at the frame and providing chordal tension throughout substantially the whole area of the diaphragm.

"12. A diaphragm includin a rigid periph-- eral stretching frame, a vi ratory portion within the frame provided with a large number of radially tensioned members of substantially the same cross-sectional area throughout their lengths crossing each other at the center of the vibratory portion, ex-

tending therefrom to the frame like the spokes of a wheel, whereby all parts of the a diaphragm may be vibrated by or vibrate the center, and also means tofprovide chordal tension in the vibratory portion.

. 13. The combination of an anchorage frame, tensioned vibratory members crossing one above another thereln near the centre of united to'the radially tensioned members where adjacent thereto.

15. The combination of a rigid" anchorage frame, a vibratory diaphragm therein provided .with an attachment portion, the maa centre member near the terial of the diaphragm being concentrated v at said portion and radiating to the frame under radial tension, said material also being to said portion.

or be driven and means'imperforate to .air connected to the filaments where adjacent ments" under chordal tension a the frame external 16. A rigid anchorage frame, a multiplicity of spaced, tensioned vibratory filaments anchored thereon, means connected to the filaments whereby the filaments may drive thereto and spanning the spaces between adjacent filaments. a

17. The combination of a'stationary' anchorage frame provided with vibratory diahragmanchored at the frame, tensioned th radially and chordally, said diaphragm including numerous radially tensioned fila- 18. Aidiaphragm provided with a stationary peripheral anchorage means, a vibratory POIYtIOILSUPP OITtGd thereby and including, a skeleton framework, driving means secured at the framework; whereby the vibratory portion may drive or be driven,said frameand numerous chordally tensioned work including tensionedmembers extending 25 from said driving means to, said anchorage means and imperforate means so carried by the members as to vibrate in synchronism therewith.

19. A stationary peripheral anchorage frame, a vibratory framework, the outer edge whereof is substantially flat, within the frame and including a large number of separate tensioned members anchored at the frame and imperforatemeans mounted upon the framework, intermediately connected to air connected to the members where adjacent thereto and spanning the spaces between adjacent members. L

" CHARLES MESSIOK. 

